Agilent 84904, 6, 7K/L Programmable Step Attenuators

Transcription

1 Agilent 84904, 6, 7K/L Programmable Step Attenuators Data Sheet High Accuracy,Excellent Reliability, Long Life Features and description DC to 26.5 GHz, DC to 40 GHz frequency coverage Optional calibration data 0 to 11 db, 70 db, 90 db 1 db steps, 10 db steps High accuracy Excellent reliability, long life Exceptionally low insertion loss These attenuators offer typical repeatability of ±0.03 db max 5 million cycles per section. This family of programmable step attenuators offers coaxial measurements to 26.5 GHz (K models) or to 40 GHz (L models), in a compact, rugged design. The first model in this family is the Agilent Technologies 84906K/L, which offers outstanding performance with an attenuation range of 0 to 90 db in 10 db steps. Other models include the Agilent 84904K/L, with 0 to 11 db of attenuation in 1 db steps, and the Agilent 84907K/L, with 0 to 70 db of attenuation in 10 db steps. This latest design evolution sets new standards for size and performance. High attenuation accuracy and low SWR are achieved through the use of miniature thin-film attenuation cards composed of high-stability tantalum nitride film on a sapphire substrate. Insertion loss performance is outstanding, with less than 2 db of loss at 26.5 GHz and only 2.4 db at 40 GHz (figure 1). Figure 1. Insertion loss The compact size of the units, 35% smaller than the 8495/7 (26.5 GHz) family, allows for easy integration into instruments and ATE systems. This family of step attenuators offers three connector types. For operation to 40 GHz, the 84904/6/7L models offer either the 2.4 mm connector, which is recommended for top performance and for rugged and repeatable connections, or the 2.92 mm connector, which is compatible with SMA and 3.5 mm connectors but is more delicate. For operation to 26.5 GHz, the 84904/6/7K models offer the 3.5 mm connector. This connector is compatible with SMA and 2.92 connectors, but is more rugged. Each model in the 84904/6/7K and L family comes with two female connectors (standard) or may be ordered with one female and one male connector for easy insertion into a microwave chain or to combine the 1 db step

2 84904 with a 10 db step or to cover an attenuation range of 121 db or 81 db in 1 db steps. Individual calibration data reports of attenuation and SWR are available. This data, measured with an Agilent automatic network analyzer, can be ordered as Option 8490XX-UK6. Attenuation switching and control These units feature the same small solenoids and switching circuits as the Agilent Technologies 8494/5/6/7 step attenuator family. Switching time is a maximum of 20 milli-seconds, including contact settling time. Once switched, the units are latched with permanent magnets, capable of withstanding shocks over 10 Gs. The solenoids automatically disconnect after switching, which minimizes the attenuators power requirements and simplifies the driver circuit design (figure 3). Solenoids are available in either 24 volt (standard, Option 8490xx-024), 15 volt (Option 8490xx-015), and 5 volt (Option 8490xx- 011) ranges to fit your instrument or system requirements. The units come equipped with 10-pin DIP headers for connecting dc control lines. Available accessories include a 203 mm (8 inch) or 406 mm (16 inch) ribbon cable with DIP-type connectors that is compatible with standard 14-pin DIP IC sockets ( or , respectively). Alternatively, a 1524 mm (5 foot) cable with free wires for direct soldering ( ), or a 1524 mm (5 foot) drive cable that connects to the 11713B/C attenuator/switch driver, allowing for easy integration into GPIB-controlled automatic test systems ( ), may be ordered. Selection switching Figure 2 shows one attenuator section schematic. Each section utilizes one solenoid with dual coil windings, one coil to switch in the attenuator card (e.g. 10 db) and one coil to switch in the thru line (0 db). Figure 2. Section electrical diagram With positive voltage applied to the common pin, the state (attenuator card or thru line) of a particular section is determined by connecting its attenuator card pin or thru pin to a negative voltage or ground. Figure 4 defines the pin assignments and wire color code for the /60002/ drive cables. Table 1 is a solenoid drive pin and attenuation guide. Table 2 (on page 4) defines recommended attenuator section activation. As a section is switched, the internal contacts of the activated coil open, thus shutting off current flow. At the same time, the internal contacts for the other coil close so that it can be activated when desired. Figure 3 shows a section that has been switched to the attenuator card position (note the closed thru line coil contact). The switching is break-before-make type, thus a momentary interruption of the RF signal occurs at switching. Although all sections can be switched simultaneously, the attenuator driver must not allow both pins of the same section (e.g. Section 1, pins 1 and 2) to be activated concurrently, or else that section would cycle rapidly. All terminals are floating, so bipolar or unipolar power supplies can be used. Figure 3. Driver and indicator circuits for one section of an Agilent 84904, 6, 7 K/L 2

3 Typical driver circuit Figure 3 shows an economical TTL compatibility driver circuit for a single attenuation section which utilizes and IC relay driver and an inverter. A TTL HI input to the driver switches in the attenuation card, while a LO will activate the thru line for that section. This provides a complimentary driver for the section which assures that only one solenoid of the pair is activated at a time. Diode protection is required to protect the IC from the solenoid voltage flyback. Switch position can be indicated remotely by utilizing the open and closed states of the internal coil contacts. Connected at A and B in figure 3 are two indicator circuits, one providing a TTL output and one that activates an LED. These circuits will output a TTL HI (LED lamp ON ) if the attenuation card is in the RF circuit, and will output a TTL LO (LED lamp OFF ) if the thru line is in the RF circuit. Since current is drawn through the coil for these circuits, inadvertent switching is prevented by limiting the current to 5 ma. Agilent Technologies assumes no responsibility for the use of any circuits described herein and makes no representation or warranties, express or implied, that such circuits are free from patent infringement. Drive cables pin DIP to 60 long ribbon cable pin DIP to 14 pin DIP, 8 long pin DIP to 14 pin DIP, 16 long pin DIP to 12 pin Viking connector, 60 long. Used with 11713A driver pin DIP to (4) 4 pin BERG connectors, 30 long. Used with 87130A or 70611A driver Figure 4. Attenuator switching pinout Table 1. Solenoid pin and attenuation guide Section: Section 1 Section 2 Section 3 Section 4 Model Number Thru Line Attn Card Thru Line Attn Card Thru Line Attn Card Thru Line Attn Card 84906K/L Attenuation (db) Actuating pin plug Pin number /60003 flat Header pin number K/L Attenuation (db) Actuating pin plug Pin number /60003 flat Header pin number K/L Attenuation (db) Actuating pin plug Pin number /60003 flat Header pin number Pin 10 is +V Supply 3

4 Table 2. Attenuator section activation guide Recommended switching sequence: The following switching sequence (ie. which 30 db section to use for the 84906K/L or which 4 db section for the 84904K/L should be followed to insure performance to specs. Attenuation selected 84906K/L 0 db 10 db 20 db 30 db 40 db 50 db 60 db 70 db 80 db 90 db Section 1 (10 db) X X X X Section 2 (20 db) X X X X Section 3 (30 db) X X X X X X X Section 4 (30 db) X X X X 84907K/L 0 db 10 db 20 db 30 db 40 db 50 db 60 db 70 db Section 1 (10 db) X X X X Section 2 (20 db) X X X X Section 3 (40 db) X X X X 84904K/L 0 db 1 db 2 db 3 db 4 db 5 db 6 db 7 db 8 db 9 db 10 db 11 db Section 1 (1 db) X X X X X Section 2 (2 db) X X X X X X Section 3 (4 db) X X X X X X X X Section 4 (4 db) X X X X Switching notes: Pins relate to 10-pin attenuator header as shown (Table 1), NOT terminating connector on any attached drive cable. Solenoids are magnetic latching type; drive voltage may be removed after switching. Current is self-interrupting in less than 20 ms. 4

5 GPIB attenuator/switch driver Employing programmable step attenuators and switches in an automatic test system becomes an easy task when the Agilent 11713B/C attenuator/switch driver is specified into the system. The 11713B/C has all of the necessary features to provide GPIB, USB, or LAN control of up to four programmable attenuators of the 84904/6/7 series, and concurrently up to four electromechanical switches (e.g., the 8671B or 8762 Series). The 11713B/C includes an integral power supply (with short circuit protection) that can simultaneously provide 125 milliamps at 24 volts to all contacts for control of the attenuators and switches, so no external power supply is needed. Connecting between the 11713B/C and the 84904/6/7 step attenuators is easy with the drive cable. The 11713B/C also features convenient front panel keys so the user can manually activate the individual attenuation sections and switches when in the local mode. Switching time for the drivers is less than 10 milliseconds. Optional calibration data for the Agilent 84904/6/7 Use of calibration data (i.e., accuracy, recorded, data of a device s characteristics) has always been an effective means of reducing measurement uncertainty at RF and microwave frequencies. Step attenuators have long been used as reference standards in the measurement of gain, attenuation, and receiver sensitivity. Since the accuracy specifications include margins for frequency response and unit-to-unit variations, calibration data can improve overall measurement uncertainty. Calibration data is available as Option 8490xx-UK6 and is generated from measurements made by an Agilent network analyzer. Option 8490xx-UK6 provides a tabular list of attenuation and reflection coefficients in 250 MHz steps from 1500 MHz to 40 GHz. Measurements are traceable to NIST (National Institute of Standards and Technology, formerly NBS) standards and feature very low measurement uncertainties (See tables 3 and 4). For devices with option 8490xx-006 and option 8490xx-106, option 8490xx-UK6 and NIST traceability are not available. Frequency Range (GHz) dc to 12.4 ± to 26.5 ± to 34 ± to 40 ±.028 Table 4. Agilent 84904/6/7K/L attenuation data uncertainties Table 3. Agilent 84904/6/7K/L reflection coefficient data uncertainty Attenuation (db) dc to 20 GHz 20 to 26.5 GHz 26.5 to 40 GHz 0 ± 0.12 ± 0.12 ± ± 0.16 ± 0.24 ± ± 0.16 ± 0.25 ± ± 0.17 ± 0.30 ± ± 0.32 ± 0.47 ± ± 0.36 ± 0.54 ± ± 0.36 ± 0.54 ± ± 0.52 ± 0.72 ± ± 0.50 ± 0.52 ± ± 0.66 ± 0.91 ±

6 Attenuator Setting Attenuation accuracy (±db; referenced from 0 db setting): 84907K/L K/L Attenuator setting Frequency range dc to 40 GHz K/L Attenuator setting (db) Frequency range dc to 18 GHz to 26.5 GHz to 40 GHz Step-to-step accuracy is the maximum variation from the nominal step size when changing attenuation values. It is a second specification on accuracy, and is used in combination with the absolute accuracy specifications to limit maximum allowable variation from nominal. Typical step-to-step accuracy for the 84906L and 84907L is ±0.6 db to 26.5 GHz, ±0.9 db to 40 GHz; for the 84904L is ±0.3 to 26.5 GHz, ±0.4 to 40 GHz. 2. Attenuation accuracy to 26.5 GHz for K models. Specifications Insertion loss (in db 0 db position, f = freq. in GHz) 84904K/L 84906K/L 84907K/L ( xf) ( xf) ( xf) SWR Connector Option dc to 12.4 GHz 12.4 GHz to 34 GHz 34 GHz to 40 GHz SWR Connector Option dc to 12.4 GHz L models K models 84904L with K L with K L with K L with K L with K L with K L with L with L with L with L with L with Attenuation temperature coefficient Less that db/db/c Power sensitivity db/watt RF Input power (max.) 1 Watt average, 50 Watts peak (10 μs max. pulse width) Life (min.) 5 million cycles per section Repeatibility ±0.03 db max 5 million cycles per section, typical Environmental capabilities (Up to 5 million cycles) Temperature, operating 20 C to +75 C Temperature, non-operating 55 C to +85 C Altitude, operating 4,570 meters (15,000 ft.) Altitude, non-operating 13,700 meters (50,000 ft.) Humidity Cycling 5 days, 40 C at 95% RH with condensation 12.4 GHz to 34 GHz Shock operating 10 Gs, six ms, on six sides, three blows Shock, non-operating 500 Gs, 1.8 ms, in six directions Vibration, operating 5 Gs, Hz EMC Radiated interference is within the requirements of MIL-STD-461 method RE02, VDE 0871 and CISPR Publication II

7 Mechanical Information Net weight 84904K/L 84906K/L 84907K/L 291 grams 291 grams 229 grams (10.3 oz) (10.3 oz) (8.1 oz) Mounting position (any) RF connectors 2.4 mm connectors standard, L models only 2.92 mm (SMA compatible), L models only 3.5 mm (SMA compatible), K models only Switching speed Maximum 20 msec including settling time Solenoids Coil voltage Switching current Option V 20 to 30 V) 125 ma (at 24 V) 190 Ω Option V (13 to 22 V) 188 ma (at 15 V) 80 Ω Option V (4.5 to 7 V) 325 ma (at 5 V) 17 Ω Nominal coil impedance 1. 1 Current per section; approximately 10 msec duration before internal contacts open the coil circuit Figure 5. Dimensions are in millimeters and inches. 7

8 Ordering information Programmable step attenuators 84904K 0 to 11 db, 1 db steps; dc to 26.5 GHz 84904L 0 to 11 db, 1 db steps; dc to 40.0 GHz 84906K 0 to 90 db, 10 db steps; dc to 26.5 GHz 84906L 0 to 90 db, 10 db steps; dc to 40.0 GHz 84907K 0 to 70 db, 10 db steps; dc to 26.5 GHz 84907L 0 to 70 db, 10 db steps; dc to 40.0 GHz Options To add options to a product, use the following ordering scheme: Model: 84904/6/7x (x = K, L) Model options: 84904/6/7x-opt#1 or 84904/6/7x-opt#2 Supply voltage (must choose one) 84904/6/7x V dc supply voltage 84904/6/7x V dc supply voltage 84904/6/7x V dc supply voltage (standard option) RF connectors (must choose one) 84904/6/7K /6/7K /6/7L /6/7L /6/7L /6/7L mm female connector, 3.5 mm female connector (standard option) 3.5 mm male connector, 3.5 mm female connector 2.92 mm female connector, 2.92 mm female connector (UK6 not available with this option) 2.4 mm male connector, 2.4 mm female connector 2.4 mm female connector, 2.4 female connector (standard option) 2.92 mm male connector, 2.92 mm female connector (UK6 not available with this option) Calibration documentation (optional) 84904/6/7x-UK6 Calibration data Accessories (optional) pin dip plug (for attenutor connection) to 1524 mm (5 foot) ribbon cable mm (8 inch) ribbon cable with 14-pin headers, female 10-pin receptacle mm (16 inch) ribbon cable with 14-pin headers, female 10-pin receptacle Interconnect cable 10-pin dip plug to Viking connector (for use with 11713B/C) 8

9 Revised: October 14, 2010 Product specifications and descriptions in this document subject to change without notice. Agilent Technologies, Inc. 2008, 2009, 2010 Printed in USA, November 1, E